WO2020211268A1

Movatterモバイル変換

Info

Publication number: WO2020211268A1
Application number: PCT/CN2019/105035
Authority: WO
Inventors: 吴财芳; 刘宁宁; 房孝杰; 韩江; 张二超; 蒋秀明
Original assignee: China University of Mining and Technology CUMT; China University of Mining and Technology Beijing CUMTB
Current assignee: China University of Mining and Technology CUMT; China University of Mining and Technology Beijing CUMTB
Priority date: 2019-04-17
Filing date: 2019-09-10
Publication date: 2020-10-22
Anticipated expiration: 2021-10-17
Also published as: AU2019427989A1; AU2019427989B2; CN109973058A; CN109973058B

Abstract

Disclosed are a single-well drainage-production device and method for a double-layer superposed coal bed gas system. The device comprises an upper-layer coal bed gas system extraction end (20), a lower-layer coal bed gas system extraction end (21) and a ground drive device (1), wherein an outer sleeve (10) is arranged inside a coal bed gas well, the upper-layer coal bed gas system extraction end (20) and the lower-layer coal bed gas system extraction end (21) are both arranged inside the outer sleeve (10), and an inner sleeve (9) is sleeved on an inner wall of one side of the outer sleeve (10); a pump hanging system (22) is arranged inside the inner sleeve (9), a pump hanging system (22) is also arranged in an annular space between the inner sleeve (9) and the outer sleeve (10), and both pump hanging systems (22) are connected to the ground drive device (1); and the inner sleeve (9) and the pump hanging system (22) constitute the lower-layer coal bed gas system extraction end (21), and the annular space of the inner sleeve (9) and the outer sleeve (10) and the pump hanging system (22) constitute the upper-layer coal bed gas system extraction end (20). According to the device, two independent drainage-production spaces can be respectively formed in a single shaft, such that inter-system interference during drainage-production can be prevented, and the cost can also be reduced.

Description

Translated fromChinese

一种双层叠置含煤层气系统单井排采装置及排采方法Single well drainage device and drainage method of double-stacked coalbed methane system

技术领域Technical field

本发明涉及煤矿开采技术领域，特别是涉及一种双层叠置含煤层气系统单井排采装置及排采方法。The invention relates to the technical field of coal mining, in particular to a single well drainage device and a drainage method of a double-stacked coal-bed methane system.

背景技术Background technique

多煤层区煤层气藏呈现出与单一煤层不同的成藏特征，煤层群广泛发育的背景使其在垂向上具有双层甚至多层叠置独立含煤层气系统的特点，各独立含煤层气系统间相互独立，含煤层气系统内部相互统一。系统间合层排采往往导致层间干扰，以至于起到1+1<1的效果，不利于煤层气产能释放。现有的煤层气开采井型在多层叠置煤层气藏区应用较为局限，严重的层间干扰致使多层叠置煤层气藏区煤层气井产量偏低，无法达到商业化开发的目的。The coalbed methane reservoir in the multi-coal area shows different accumulation characteristics from a single coal seam. The background of the extensive development of coal seam groups makes it have the characteristics of two-layer or even multi-layer independent coal-bed methane systems in the vertical direction. They are independent of each other and unified within the coal-bed methane system. The inter-system combined layer drainage often leads to inter-layer interference, so that it has an effect of 1+1<1, which is not conducive to the release of CBM production capacity. The existing CBM mining well types are more limited in the application of multi-layer stacked coal-bed methane reservoirs. The severe interlayer interference causes the low production of coal-bed methane wells in the multi-layer stacked coalbed methane reservoirs, which cannot achieve the purpose of commercial development.

针对多层叠置煤层气藏区开发井型受限的现状，专利文献CN104295292A,专利名称为“多层叠置煤层气系统开采井设计方法”中指出在同一钻井平台上分别向各个含气系统层各钻进一口煤层气垂直井，这虽然可以有效缓解层间干扰，但多煤层区单一系统煤厚普遍较小，煤层气储量有限，这种开采方法大幅度增加了开采成本，经济性差，且在一个较小的钻井平台内钻进两口甚至数口井，当上层含煤层气系统压裂时很可能会影响邻近排采下层含气系统煤层气的气井井筒的稳定性，该方法在经济性和可行性方面均存在不容忽视的问题。In view of the current situation of limited development well types in multi-layered coalbed methane reservoir areas, the patent document CN104295292A, with the patent title "Design method for multi-layered coalbed methane system mining wells", points out that each gas-bearing system layer is provided on the same drilling platform. Drilling a vertical coalbed methane well can effectively alleviate the inter-layer interference, but the coal thickness of a single system in the multi-coal area is generally small, and the reserves of coalbed methane are limited. This mining method greatly increases the mining cost and is economical. Two or even several wells are drilled in a small drilling platform. When the upper coalbed methane system is fracturing, it is likely to affect the stability of the gas well bores adjacent to the lower coalbed methane system. This method is economical and economical. There are problems that cannot be ignored in terms of feasibility.

发明内容Summary of the invention

为了克服上述现有技术的不足，本发明提供了一种双层叠置含煤层气系统单井排采装置及排采方法。In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a single well drainage device and a drainage method for a double-stacked coal-bed methane system.

本发明所采用的技术方案是：一种双层叠置含煤层气系统单井排采装置，包括上层含煤层气系统抽采端、下层含煤层气系统抽采端和地面驱动装置，在煤层气井内设置有外套管，所述上层含煤层气系统抽采端与下层含煤层气系统抽采端均设置在外套管内部，所述外套管一侧内壁套设有内套管，所述内套管外壁与外套管内壁不重叠，所述内套管直径等于外套管半径，所述内套管与外套管环空处下半段空间设置有注浆固结体，所述内套管底部和注浆固结体顶部设置有人工井底；The technical scheme adopted by the present invention is: a double-stacked single well drainage device of a coal-bed methane system, including an upper coal-bed methane system extraction end, a lower coal-bed methane system extraction end, and a ground drive device. An outer casing is arranged in the well. The upper coalbed methane system extraction end and the lower coalbed methane system extraction end are both arranged inside the outer casing, and the inner wall of the outer casing is sleeved with an inner casing. The inner casing The outer wall of the pipe does not overlap with the inner wall of the outer sleeve, the diameter of the inner sleeve is equal to the radius of the outer sleeve, the lower half of the annulus between the inner sleeve and the outer sleeve is provided with a grouting consolidation body, the bottom of the inner sleeve and Artificial bottom hole is set on the top of grouting consolidation body;

所述内套管内设置有泵挂系统，所述内套管与外套管环空处也设置有泵挂系统，所述泵挂系统均与地面驱动装置相连接；A pumping system is arranged in the inner sleeve, and the annulus between the inner sleeve and the outer sleeve is also provided with a pumping system, and the pumping system is connected to a ground driving device;

所述内套管与泵挂系统构成下层含煤层气系统抽采端，所述内套管与外套管环空处和泵挂系统构成上层含煤层气系统抽采端。The inner casing and the pumping system constitute the extraction end of the lower coalbed methane system, and the annulus between the inner casing and the outer casing and the pumping system constitute the extraction end of the upper coalbed methane system.

进一步地，所述泵挂系统包括油管，所述油管内部设置有抽油杆，并且油管下部安装有螺杆泵，所述抽油杆的顶端连接地面驱动装置。Further, the pumping system includes an oil pipe, a sucker rod is arranged inside the oil pipe, a screw pump is installed at the lower part of the oil pipe, and the top end of the sucker rod is connected to a ground driving device.

进一步地，所述螺杆泵的底部设有筛管，所述筛管底端还设有丝堵。Further, the bottom of the screw pump is provided with a screen, and the bottom end of the screen is also provided with a plug.

进一步地，所述地面驱动装置包括相连接的动力转向组件和皮带传动组件，所述皮带传动组件与发动机相连，所述动力转向组件由纵向锥齿轮、横向锥齿轮组和螺纹杆组成。Further, the ground driving device includes a connected power steering assembly and a belt transmission assembly, the belt transmission assembly is connected with the engine, and the power steering assembly is composed of a longitudinal bevel gear, a transverse bevel gear set and a threaded rod.

进一步地，所述动力转向组件的纵向锥齿轮在螺纹杆上左右移动，以适应不同尺寸的横向锥齿轮组，所述不同尺寸的横向锥齿轮组可实现双层叠置含煤层气系统以不同速率排水采气。Further, the longitudinal bevel gears of the power steering assembly move left and right on the threaded rod to adapt to the transverse bevel gear sets of different sizes, and the transverse bevel gear sets of different sizes can realize the double-stacked coal-bed methane system at different speeds. Drain gas.

进一步地，所述排采装置还包括用以固定内套管和上层含煤层气系统抽采端中油管相对位置的扶正器，所述扶正器的中心设有过电缆通道。Further, the drainage device further includes a centralizer for fixing the relative positions of the inner casing and the oil pipe in the extraction end of the upper coalbed methane system, and a cable channel is provided in the center of the centralizer.

进一步地，所述内套管内、外管壁均设有压力计电缆，所述压力计电缆底端连接压力计，压力计电缆顶端穿过过电缆通道与地表仪表相连，所述压力计固定安装在内套管内、外管壁底部表面。Further, both the inner and outer pipe walls of the inner sleeve are provided with a pressure gauge cable, the bottom end of the pressure gauge cable is connected to a pressure gauge, the top end of the pressure gauge cable passes through the cable channel and is connected to the surface instrument, and the pressure gauge is fixedly installed On the bottom surface of the inner and outer tube walls.

一种双层叠置含煤层气系统单井排采方法，包括以下步骤：A single-well drainage and production method of a double-stacked coalbed methane system includes the following steps:

步骤一：在系统分析工作区含煤地层构造-沉积-水文耦合作用的基础上，寻找适合分层排采的双层叠置含煤层气系统区域，并将双层叠置含煤层气系统划分为上层含煤层气系统抽采端和下层含煤层气系统抽采端。Step 1: Based on the coupling effect of coal-bearing strata structure-sedimentation-hydrology in the system analysis work area, search for the double-stacked coalbed methane-bearing system area suitable for layered drainage, and divide the double-stacked coalbed methane system into the upper layer The extraction end of the coalbed methane system and the extraction end of the lower coalbed methane system.

步骤二：根据两叠置含煤层气系统抽采端煤层埋深确定内套管、外套管、油管、抽油杆长度，并选择尺寸、排量及扬程合适的螺杆泵，根据上层含煤层气系统抽采端底界埋深确定注浆固结高度；在钻井、固井之后，压裂之前，沿外套管内壁任意一侧下入内套管，并在外套管与内套管之间另一侧预留尽可能大的环空，自内套管内部注入水泥浆，水泥浆在内、外套管环空返至上层含煤层气系统抽采端底界并固结，在内套管底部和注浆固结体顶部分别布置人工井底。Step 2: Determine the length of the inner casing, outer casing, tubing, and sucker rod according to the depth of the coal seam at the extraction end of the two superimposed CBM-bearing systems, and select the screw pump with appropriate size, displacement and head, according to the upper CBM-bearing The depth of the bottom boundary of the drainage end of the system determines the grouting consolidation height; after drilling and cementing, before fracturing, run the inner casing along any side of the inner wall of the outer casing, and place the other casing between the outer casing and the inner casing. Reserve as much annulus as possible on the side, and inject cement slurry from the inside of the inner casing. The cement slurry in the inner and outer casing annulus returns to the bottom boundary of the extraction end of the upper coalbed methane system and is consolidated. Artificial bottom holes are arranged on the top of the grouting consolidation body.

步骤三：在内套管内管壁底部和内套管外管壁上层含煤层气系统抽采端底端安装压力计，将压力计电缆沿内套管内管壁和外管壁分别与两压力计相连，并对压力计及其与压力计电缆连接处进行密封处理。Step 3: Install pressure gauges at the bottom of the inner tube wall of the inner casing and the upper layer of the outer tube wall of the inner casing at the bottom of the extraction end of the coalbed methane system, and connect the pressure gauge cable to the two pressure gauges along the inner and outer walls of the inner casing Connect and seal the pressure gauge and its cable connection with the pressure gauge.

步骤四：在油管内壁底部安装螺杆泵定子，抽油杆底端连接螺杆泵转子，将丝堵、筛管、螺杆泵、油管、抽油杆下至指定深度，上、下层含煤层气系统抽采端的螺杆泵吸水口应分别位于上、下层含煤层气系统抽采端相对应的最上层煤层直接顶高度处，以保证排采过程中本系统内煤层不暴露。Step 4: Install the screw pump stator at the bottom of the inner wall of the tubing, connect the screw pump rotor at the bottom end of the sucker rod, lower the plug, screen, screw pump, tubing, and sucker rod to the specified depth, and pump the upper and lower layers of the coalbed methane system The suction port of the screw pump at the mining end should be located at the height of the direct top of the uppermost coal seam corresponding to the extraction end of the upper and lower coalbed methane system to ensure that the coal seam in the system is not exposed during the drainage process.

步骤五：根据双层叠置含煤层气系统间煤层的富水性差异选择不同尺寸的横向锥齿轮组，弱含水煤层组成的含气系统应选择直径较大的横向锥齿轮组，强含水煤层组成的含气系统应选择直径较小的横向锥齿轮组。Step 5: Choose lateral bevel gear sets of different sizes according to the difference in water richness of coal seams between double-stacked CBM systems. For gas systems composed of weak water-bearing coal seams, select lateral bevel gear sets with larger diameters and strong water-bearing coal seams. The gas-containing system should select a transverse bevel gear set with a smaller diameter.

步骤六：在外套管、内套管、油管之间的环空靠近井口处安装扶正器，压力计电缆穿过扶正器过电缆通道并与地表仪表相连，两根抽油杆顶端分别与地面驱动装置的两个横向锥齿轮组相连，每个横向锥齿轮组分别与两个纵向锥齿轮咬合，两个发动机分别通过皮带传动组件为动力转向组件供能，启动地面驱动装置，开始排采双层叠置含煤层气系统的煤层气资源。Step 6: Install a centralizer in the annulus between the outer casing, inner casing, and tubing near the wellhead. The pressure gauge cable passes through the centralizer through the cable channel and is connected to the surface instrument. The tops of the two sucker rods are driven by the ground. The two horizontal bevel gear sets of the device are connected, and each horizontal bevel gear set is engaged with two longitudinal bevel gears respectively. The two engines respectively supply power to the power steering assembly through the belt drive assembly, start the ground drive device, and start the dual stacking Set up the CBM resources of the CBM-containing system.

步骤七：排采过程中，应遵循“连续、缓慢、稳定、长期”的排采原则，通过调整为各含煤层气系统抽采端供能的发动机的功率，以及根据需要调整横向锥齿轮组的工作齿轮半径，实现对螺杆泵抽采速度的有效控制。Step 7: In the process of drainage, follow the principle of "continuous, slow, stable, and long-term" drainage, by adjusting the power of the engine that supplies energy to the extraction end of each coal-bed methane system, and adjusting the transverse bevel gear set as required The radius of the working gear can effectively control the pumping speed of the screw pump.

步骤八：抽采后期，若某一含煤层气系统抽采端随排采工作进行降压至该系统煤储层的枯竭压力，可以关闭为该含煤层气系统抽采端供能的发动机，另一含煤层气系统抽采端可继续排采，直至该含煤层气系统抽采端也排采降压至相应煤储层的枯竭压力，双层叠置含煤层气系统均降压至各自枯竭压力后，停井，从井内以与下入时相反的顺序依次取出除、内外套管外的其他组件，封井。Step 8: In the late stage of extraction, if the extraction end of a coalbed methane system is depressurized to the depletion pressure of the coal reservoir along with the drainage work, the engine that powers the extraction end of the coalbed methane system can be shut down. The extraction end of the other coal-bed methane system can continue to discharge until the extraction end of the coal-bed methane system also discharges and reduces the pressure to the depletion pressure of the corresponding coal reservoir, and the double-stacked coal-bed methane system is depressurized to each depletion After the pressure is applied, the well is stopped, and the components other than the inner and outer casing are taken out from the well in the reverse order of the run-in, and the well is sealed.

与现有技术相比，本发明的有益效果是：Compared with the prior art, the beneficial effects of the present invention are:

1、本发明中的装置结构在与大直径钻井技术相结合的基础上能够实现在单一井筒内分别形成两个独立的排采空间，避免重复钻井造成的资源浪费和成本增加，还可以防止两井或多井近距离压裂及施工带来的不便及不确定性隐患的发生。1. The device structure of the present invention can realize the formation of two independent drainage spaces in a single wellbore on the basis of combining with large-diameter drilling technology, avoid resource waste and cost increase caused by repeated drilling, and can also prevent two The occurrence of inconvenience and uncertainty caused by close fracturing of wells or multiple wells and construction.

2、在内套管内部和内、外套管的环空中分别形成下层含煤层气系统和上层含煤层气系统的动液面，在合理调控发动机功率及选择工作半径合适的横向锥齿轮组的基础上，对上、下层含煤层气系统抽采端的排水速率进行精细化控制，促进煤层气解吸，释放储层产能。2. The inside of the inner casing and the annulus of the inner and outer casings respectively form the liquid level of the lower coalbed methane system and the upper coalbed methane system, which is the basis for rational control of engine power and selection of lateral bevel gear sets with appropriate working radius Above, finely control the drainage rate at the extraction end of the upper and lower coalbed methane systems to promote the desorption of coalbed methane and release reservoir productivity.

附图说明Description of the drawings

图1为本发明双层叠置含煤层气系统单井排采装置及排采方法的结构示意图；Figure 1 is a schematic structural diagram of a single well drainage device and a drainage method of a double-stacked coalbed methane-containing system of the present invention;

图2为图1中A-A的剖面图；Figure 2 is a sectional view of A-A in Figure 1;

图3为本发明中地面驱动装置的结构示意图。Fig. 3 is a schematic diagram of the structure of the ground driving device in the present invention.

其中：1-地面驱动装置，2-压力计电缆，3-螺杆泵，4-筛管，5-丝堵，6-注浆固结体，7-压力计，8-人工井底，9-内套管，10-外套管，11-抽油杆，12-油管，13-扶正器，14-过电缆通道，15-动力转向组件，16-皮带传动组件，17-纵向锥齿轮，18-横向锥齿轮组，19-螺纹杆， 20-上层含煤层气系统抽采端，21-下层含煤层气系统抽采端，22-泵挂系统。Among them: 1- ground drive device, 2- pressure gauge cable, 3- screw pump, 4- screen pipe, 5- wire plug, 6-grouting consolidation body, 7- pressure gauge, 8- artificial bottom, 9- Inner casing, 10-outer casing, 11- sucker rod, 12- tubing, 13- centralizer, 14- cable channel, 15- power steering assembly, 16- belt drive assembly, 17- longitudinal bevel gear, 18- Lateral bevel gear set, 19-threaded rod, 20-upper coalbed methane system extraction end, 21-lower coalbed methane extraction end, 22-pumping system.

具体实施方式detailed description

为了加深对本发明的理解，下面结合附图和实施例对本发明进一步说明，该实施例仅用于解释本发明，并不对本发明的保护范围构成限定。In order to deepen the understanding of the present invention, the present invention will be further described below with reference to the drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

如图1和图2所示，一种双层叠置含煤层气系统单井排采装置，包括上层含煤层气系统抽采端20、下层含煤层气系统抽采端21和地面驱动装置1，在煤层气井内设置有外套管10，所述上层含煤层气系统抽采端20与下层含煤层气系统抽采端21均设置在外套管10内部，所述外套管10一侧内壁套设有内套管9，所述内套管9外壁与外套管10内壁不重叠，所述内套管9直径等于外套管10半径，所述内套管9与外套管10环空处下半段空间设置有注浆固结体6，所述内套管9底部和注浆固结体6顶部设置有人工井底8。As shown in Figures 1 and 2, a double-stacked single well drainage device of a coalbed methane system includes an upper coalbed methanesystem extraction end 20, a lower coalbed methane system extraction end 21, and a ground drive device 1. Anouter casing 10 is provided in the coal-bed methane well. The upper coal-bed methanesystem extraction end 20 and the lower coal-bed methanesystem extraction end 21 are both arranged inside theouter casing 10, and one side of theouter casing 10 is sheathed with Theinner sleeve 9, the outer wall of theinner sleeve 9 and the inner wall of theouter sleeve 10 do not overlap, the diameter of theinner sleeve 9 is equal to the radius of theouter sleeve 10, and the lower half of the space between theinner sleeve 9 and the outer sleeve 10 Agrouting consolidation body 6 is provided, and an artificial bottom hole 8 is provided at the bottom of theinner casing 9 and the top of thegrouting consolidation body 6.

在上述实施例中，所述内套管内设置有泵挂系统21，所述内套管9与外套管10环空处也设置有泵挂系统21，所述泵挂系统21均与地面驱动装置1相连接；所述内套管9与泵挂系统21构成下层含煤层气系统抽采端21，所述内套管9与外套管10环空处和泵挂系统21构成上层含煤层气系统抽采端20。In the above embodiment, apumping system 21 is provided in the inner sleeve, and the annulus between theinner sleeve 9 and theouter sleeve 10 is also provided with apumping system 21. Thepumping system 21 is connected to a ground drive device. 1 is connected; theinner casing 9 and thepumping system 21 constitute the lower coalbed methanesystem extraction end 21, theinner casing 9 and theouter casing 10 annulus and thepumping system 21 constitute the upper coalbed methanesystem Extraction end 20.

在上述实施例中，所述泵挂系统21包括油管12，所述油管12内部设置有抽油杆11，并且油管12下部安装有螺杆泵3，所述抽油杆11的顶端连接地面驱动装置1；所述螺杆泵3的底部设有筛管4，所述筛管4底端还设有丝堵5。In the above embodiment, thepumping system 21 includes anoil pipe 12 with asucker rod 11 arranged inside theoil pipe 12, and a screw pump 3 is installed at the lower part of theoil pipe 12, and the top end of thesucker rod 11 is connected to a ground driving device 1; The bottom of the screw pump 3 is provided with a screen 4, and the bottom of the screen 4 is also provided with a plug 5.

如图3所示，所述地面驱动装置1包括相连接的动力转向组件15和皮带传动组件16，所述皮带传动组件16与发动机相连，所述动力转向组件15由纵向锥齿轮17、横向锥齿轮组18和螺纹杆19组成；所述动力转向组件15的纵向锥齿轮17在螺纹杆19上左右移动，以适应不同尺寸的横向锥齿轮组18，所述不同尺寸的横向锥齿轮组18可实现双层叠置含煤层气系统以不同速率排水采气。As shown in Figure 3, the ground driving device 1 includes apower steering assembly 15 and abelt drive assembly 16 connected to each other. Thebelt drive assembly 16 is connected to the engine. Thepower steering assembly 15 is composed of alongitudinal bevel gear 17, a transverse cone The gear set 18 and the threadedrod 19 are composed; thelongitudinal bevel gear 17 of thepower steering assembly 15 moves left and right on the threadedrod 19 to adapt to the transverse bevel gear set 18 of different sizes, which can be Realize the double-stacked coalbed methane system to drain gas at different rates.

在上述实施例中，所述排采装置还包括用以固定内套管9和上层含煤层气系统抽采端20中油管12相对位置的扶正器13，所述扶正器13的中心设有过电缆通道14；所述内套管9内、外管壁均设有压力计电缆2，所述压力计电缆2底端连接压力计7，压力计电缆2顶端穿过过电缆通道14与地表仪表相连，所述压力计7固定安装在内套管9内、外管壁底部表面。In the above embodiment, the drainage device further includes acentralizer 13 for fixing the relative position of theinner casing 9 and theoil pipe 12 in the upper coalbed methanesystem extraction end 20, and thecentralizer 13 is provided with acentralizer 13 in the center.Cable channel 14; both the inner and outer pipe walls of theinner sleeve 9 are provided with apressure gauge cable 2. The bottom end of thepressure gauge cable 2 is connected to apressure gauge 7, and the top end of thepressure gauge cable 2 passes through thecable channel 14 and the surface instrument Thepressure gauge 7 is fixedly installed on the bottom surface of the inner and outer tube walls of theinner sleeve 9.

在上述实施例中，双层叠置含煤层气系统单井排采方法，包括以下步骤：In the above-mentioned embodiment, the single-well drainage and production method of the double-stacked CBM-bearing system includes the following steps:

步骤六：在外套管、内套管、油管之间的环空靠近井口处安装扶正器，压力计电缆穿过扶正器过电缆通道并与地表仪表相连，两根抽油杆顶端分别与地面驱动装置的两个横向锥齿轮组相连，每个横向锥齿轮组分别与两个纵向锥齿轮咬合，两个发动机分别通过皮带传动组件为动力转向组件供能，启动地面驱动装置，同时开始排采双层叠置含煤层气系统的煤层气资源。Step 6: Install a centralizer in the annulus between the outer casing, inner casing, and tubing near the wellhead. The pressure gauge cable passes through the centralizer through the cable channel and is connected to the surface instrument. The tops of the two sucker rods are driven by the ground. The two transverse bevel gear sets of the device are connected, and each transverse bevel gear set is engaged with two longitudinal bevel gears respectively. The two engines respectively supply energy for the power steering assembly through the belt drive assembly, start the ground drive device, and start the dual discharge at the same time. Stack the coal-bed methane resources of the coal-bed methane system.

本发明的实施例公布的是较佳的实施例，但并不局限于此，本领域的普通技术人员，极易根据上述实施例，领会本发明的精神，并做出不同的引申和变化，但只要不脱离本发明的精神，都在本发明的保护范围内。The embodiment of the present invention discloses a preferred embodiment, but it is not limited to this. Those of ordinary skill in the art can easily understand the spirit of the present invention and make different extensions and changes based on the above embodiments. However, as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.